可控电抗器在我国超/特高压电网中的应用

Application of Controllable Reactors in China’s Power Grid at Extra and Ultra Voltage Level

特高压线路充电大,限制过电压和无功补偿矛盾突出,通过对特高压线路特性和典型系统分析可知,为解决这一矛盾,需要在长距离重载线路及潮流变化大的外送线路上安装特高压可控电抗器。特高压线路采用可控电抗器需要在500kV线路上挂网试验运行,以解决可控电抗器在我国电网应用中的相关技术问题。研究表明:可控电抗器对系统暂态稳定的影响主要依赖于它在工况下的状态,而与其调节方式关系不大;而可控电抗器对系统动态稳定的影响则不仅与其工况下的状态相关,更主要的是与可控电抗器的调节方式相关,其中,无滞后环节平滑调节电抗器和多次动作分级投切电抗器在工况满负荷的情况下对系统具有最好的作用。

Because of the relatively high charging capacitance of Ultra High Voltage transmission lines, the contradiction between UHV transmission line＇s over-voltage limitation strategy and its reactive power compensation strategy becomes prominent, while fix controllable reactors on UHV lines whose load is heavy or changing greatly may be an effective way to solve this contradiction. Through analyzing the typical system＇s characteristic and UHV transmission line＇s characteristic, the strategy by controllable reactor is presented in this paper. Authors also point out that the controllable reactor＇s application in UHV network should be tested on existing 500kV system fn＇st, which will be helpful for the implementation of controllable reactor＇s on UHV network in future. This study shows that the effect on transient stability by controllable reactors depend on their capacity in steady operation, while for dynamic stability, mode of control is more important than capacity in steady operation. The controllable reactors, which regulate smoothly without delay or switch step by step act best, of cause their rating capacity are all put into operation in steady state.